Toyota Tundra Service Manual: Terminals Of Ecu

TERMINALS OF ECU

1. CHECK AIR CONDITIONING AMPLIFIER

(a) Disconnect the J19 air conditioning amplifier connector.

(b) Measure the resistance and voltage according to the value(s) in the table below.

Terminal No. (Symbol)	Wiring Color	Terminal Description	Condition	Specified Condition
J19-1 (IG+) - J19-14 (GND)	B - W-B	Ignition power supply	Ignition switch ON	11 to 14 V
J19-1 (IG+) - J19-14 (GND)	B - W-B	Ignition power supply	Ignition switch OFF	Below 1 V
J19-21 (B) - J19-14 (GND)	GR - W-B	Battery power source	Always	11 to 14 V
J19-14 (GND) - Body ground	W-B - Body ground	Ground	Always	Below 1 Ω
J19-37 (LIN1) - J19-14 (GND)	SB - W-B	LIN communication signal	Ignition switch ON	Pulse generation

(d) Measure the voltage according to the value(s) in the table below.

Terminal No. (Symbol)	Wiring Color	Terminal Description	Condition	Specified Condition
J19-38 (RDEF) - J19-14 (GND)	Y - W-B	Defogger relay	Ignition switch ON, rear window defogger switch off	11 to 14 V
J19-38 (RDEF) - J19-14 (GND)	Y - W-B	Defogger relay	Ignition switch ON, rear window defogger switch on	Below 1 V

2. CHECK AIR CONDITIONING CONTROL ASSEMBLY

(a) Disconnect the J127 air conditioning control assembly connector.

(b) Measure the voltage and resistance according to the value(s) in the table below.

Terminal No. (Symbol)	Wiring Color	Terminal Description	Condition	Specified Condition
J127-4 (IG+) - J127-5 (GND)	Y - W-B	Ignition power supply	Ignition switch ON	11 to 14 V
J127-4 (IG+) - J127-5 (GND)	Y - W-B	Ignition power supply	Ignition switch OFF	Below 1 V
J127-5 (GND) - Body ground	W-B - Body ground	Ground	Always	Below 1 Ω
J127-7 (STX) - J127-5 (GND)	SB - W-B	LIN communication signal	Ignition switch ON	Pulse generation

Toyota Tundra Service Manual > Navigation System: Vehicle Speed Signal Circuit between Navigation Receiver Assembly and Combination Meter
DESCRIPTION The navigation receiver assembly receives a vehicle speed signal from the combination meter assembly to control the ASL function. HINT: A voltage of 12 V or 5 V is output from each ECU and then input to the combination meter assembly. The signal is changed to a pulse signal at the transi ...

Toyota Tundra Owners Manual